Multiple-size tongs



Dec. 13, 1927.

R. ADAMS MULTIPLE SIZE TONGS -F iled Nov. 11. 1924 2 Sheets-Sheet 2 Patented Dec. 13, 1927.

UNITED STATES 1,652,551 PATENT OFFICE.

ROBERT ADAMS, 01 LOS ANGELES, CALIFORNIA, ASSIGNOR T WILLIAM WEBSTER WILSON, OF LOS ANGELES, CALIFORNIA.

MULTIPLE-SIZE TONGS.

Application filed November 11, 1924. Serial No. 749,126H E I E D This invention has to do with tongs that are adaptable to work of different sizes; and the general object of the invention is to make such tongs have a work gripping or contacting surface that will give a good, broad and comparatively flat engagement with different sizes of work.

Heretofore, in tongs that have been adjustable or, in some manner, applicable to take pipe or other work of different sizes, the work engaging members have been so formed on their work engaging surfaces that it has been impossible to obtain a good contact with more than one size of pipe. For instance, in tongs .where the work is encircled by several interconnected jaws or segments, those j aws or segments have commonly been formed or bored to have arcuate surfaces of a certain diameter, and that would accordingly fit flatly only upon a single diameter of work. On work of all other diameters there has thus been practically only a point or line of contact of each segment or jaw with the work.

My invention comprises primarily the for-' mation of work engaging surfaces in such a manner as to give a comparatively broad and fiat engagement with any size of work ,to which the tongs are adapted. In explaining the invention, in the following description, I shall explain it as applied specifically to that type of tongs known as the \Vilson ton s, which are largely used in oil well work Thus I explain my invention as applied to such tongs as are set out in the patents to Elihu C. Wilson, Patent No. 1,561,963, dated November 17, 1925, and Patent No. 1,575,141, dated March 3, 1926, and the copending' application of Robert Adams, on self closing tongs, Serial Number 746,257, filed October 28, 192 But it will be understood that the explanation of my invention as applied to such specific type of tongs is not tobe taken as a limitation upon the invention itself.

For the purposes of the description, I show in the accompanying drawings such tongs with the invention applied thereto, and in these drawings Fig. 1 is a plan showing the tongs closed about a smaller pipe;

Fig. 2 is a plan, with parts in section, showing the tongs closed about a larger P i s F g. 31s a plan, with parts in section,

showing the tongs equipped with reducing bushings, and applied to the larger size of pipe that it will take when equipped with such bushings F Fl%. 4 is a detailed section on line 4- 1 of Fig. 5 is a more or less diagrammatic section showing more clearly the formation of the work engaging surfaces; and

Fig. 6 is a diagram showing a-n1odified form of Work engaging face. i

The specific type of tongs shown in the drawings involve a lever handle 10 with a pluralityof pipe encircling segments or jaws, so pivoted to the handle that movement of the handle constricts the jaws about the work. Thus, for instance, the handle has two pivots at 11 and 12, to which the jaws 13 and 14 are connected, and these two jaws 13 and 14 carry two outer jaws. 1,5 and 16 pivoted to them at pivots 17 and 18. One of the outer aws carries the spring pressed latch 19, whose latching shoulder 20 is adapted to engage either of two lug shoulders 21 and 22 on the other outer jaw 16.. By the latch thus engaging either of the shoulders, and also by movement of handle 10, the four jaws may surround either a small sized pipe P, as shown in Fig. 1, or a larger sized pipe or the collar G as shown in Fig. 2.

In the preferred practical form of my invention, the aws each have an inner pipe engaging surface of a pluralityof curvatures. Thus, in'the particular tongs illustrated, where the tongs are made to be applicable to two different sizes of work, each jaw is provided with pipe engaging surfaces of two curvatures. Thus, for instance as on the jaw 15, it will be noted that the curvature between the two dash lines aa and 6-7), is a curvature corresponding to that of the smaller pipe P, whereas the curvature from line a-a and line 6-?) to the ends of the jaw is a curvature corresponding to that of the larger size pipe or collar C. These two curvatures are, in practice, formed as follows: The tongs are first set in the position shown in Fig. 2, that is, in a position to encircle the larger size pipe or collar, and then the inner faces of the jaws are bored out to a diameter equal to that of the larger size pipe or collar. have but a single curvature, the jaws having curved faces that would then fit flatly upon the larger size pipe or collar through- In this condition the jaws corresponding to that of the smaller size pipe, leaving intact the two end faces of each jaw that'have curvatures corresponding to the curvature of the larger size pipe or collar. Thus, when the tongs are applied to the smaller size pipe, the jaws each seat on the pipe flatly throughout those portions of their faces that are of the smaller diameter curvature; while, when the tongs are applied to the larger size pipe or collar, they contact and seat flatly throughout those portions that have curvatures on the larger diameter- It will, of course, be readily understood that the scheme of curvatures. here described is not limited necessarily to curvatures of only two diameters, as it will be obvious that in tongs applicable to three or more different diameters of work, the jaw faces may be bored or otherwise surfaced to have curvatures on those three or more different diameters. However, as the invention is here described as applied to a tongs applicable to two difierent sizes of work, the jaws are shown with two diflerent curvatures.

The tongs shown in these drawings may be adapted to take other difi'erent sizes of work by the use of bushings B such as shown in Figs. 3 and 4. These bushings may be made easily attachable to and detachable from the tongs as, for instance, by being held in place by cap screws 30, and they are curved at their back faces to seat back against the face curvatures of the jaws. For instance, a simple way of making the bushings is to make the curvature of their back faces the same as the smaller diamter curvature of the jaws. The front or inner faces of these bushings may also have surfaces of multiple curvature, in this case faces of double curvature. For instance, in these bushings the curvature between the two lines aa and bb may be the curvature to take a smaller size pipe P as is indicated in Fig. 5, while the curvature between said lines a-a and 6-4) and the ends of the bushings may be such as to take a larger size pipe or a collar C as is shown in Fig. 3. The bushings thus enable the tongs to be used on pipes or collars of various different sizes, and, of course, several sets of bushings of difierent thicknesses may be applied and used in connection with a given set of tongs. But another advantage of the bushings is in this: that by the use of such bushings the tongs gripping surfaces.

may be made to accurately fit upon a pipe of a diameter very slightly different from the pipe which the tongs Wlll fit without the bushings. In a tongs of the kind here illus trated, it is advantageous to have the two lug shoulders 21 and 22 spaced apart by a substantial distance in order to make the latch shoulder always drop over and engage with the correct lug shoulder when the tongs are applied to a pipe without the necessity of the correct shoulder being selected by the operator; Tongs of the character herein shown are made to be automatic in their application to a pipe, as is set out in the Adams application hereinbefore mentioned. In such operation of the tongs the handle 10 is thrown around in the direction indicated by the arrow in Fig. 1, until it connects with the stop 35 on jaw 13. By'holding the handle in this position, jaw 13 is prevented from backing away from the pipe and the stop action of stop lug 36 on jaw 13 and lug 37 on jaw 15 limits the amount by which jaw 15 can back away from the pipe. With the parts in this position it is only necessary to swing the jaw 16 around to closing position on the pipe, and the latch shoulder 20 will then drop over lug shoulder 21 if the tongs are being applied to a larger sized pipe or collar; or the latch shoulder will go on and drop over lug shoulder 22 if the tongs are being applied to the smaller sized pipe. In these operations it is, of course, necessary that the two lug shoulders 21 and 22 be kept far enough apart that the latch shoulder will never have the opportunity of dropping over lug shoulder 22 when the tongs are being applied to the larger size pipe or collar. Consequently, in a tongs of this type, it may be somewhat difficult to have the tongs applicable to pipes of difierent sizes where the difference in size is comparatively slight.

But by the use of bushings it will be seen that, for instance, the larger size pipe or collar which may be taken by the tongs equipped with bushings may be very nearly the size of the smaller size pipe that may be taken by the tongs not equipped with bushings; and that in each case'the tongs makes very good contact with the pipe or collar, as a the case may be.

Fig. 5 shows, more or less diagrammatically, the difierent curvatures of the work Here the diflerence in curvatures is made clear and it is made clear how only surfaces of one curvature will conlli) tact and grip with a pipe of a given diameter, and that a flat contact is had over a considerable area. In Fig. 5 a smaller size pipe is shown and it will be seen that it is gripped over the area between the lines a0; and b-b. This area on the bushing B (and likewise the corresponding area on the jaw) has a cylindric curvature with a center at the point 0. The surfaces at the ends of the bushing and aw are of a cylindric curvature whose center is at the point If it were desired to make these surfaces adaptable to another and still smaller size of pipe, a surface of another curvature would, for instance, be made as indicated by the dotted lines 8, having a center, for instance, at the point 0 Carried to an ultimate con clusion, this provision of surfaces of different curvatures on the faces of the jaws or segments amounts to the pipe gripping face of any one jaw having a varying curvature. In other words, it amounts to the jaw, for instance, having a face of a curvature that varies from point to point along its length. If the curvature from end to end of the jaw constantly varied, in strict theory there would be, of course. but a line of contact with each individual size of pipe. But, if the variation in curvature is not very great, in practice, due to resilient compressibility of the materials of the jaws and pipe, this theoretical line of contact is expanded into a small surface of contact. Thus, for instance, the jaw may be equipped with an inner face, such as illustrated in Fig. 6. Here, for instance, the inner face F may be parabolic in contour and the curvature, say at the points 20, may be on a diameter of 6, while the curvature at the center point p may be, for instance, on a diameter of 5". A pipe of 6 diameter would theoretically contact at the two points 30, while a pipe of 5 diameter would contact at the point but the variation in curvature being small, the theoretic lines of contact are expanded into small areas of contact by reason of resilient compressibility of the materials.

However, I specifically prefer the form of gripping surface that involves a plurality of surfaces of different curvature, the curvature of each individual surface being uniform; as has been first explained in this description. In such an arrangement, if it is desired to use toothed dies, such as are commonly inset into tong jaws, those toothed dies are inset into one or more of the aws at the points of change of curvature in their surfaces. This, for instance, is illustrated at D in Figs. 1 and 5. In such position it will be readily understood that the teeth of the dies will then engage work of either size.

Having described a preferred form of my invention, I claim:

1. In a tongs, the combination of a plurality of work gripping jaws adapted collectively to surround and grip work of different sizes, the jaws having substantially similar work engaging faces and each jaw having work engaging surfaces of two different curvatures, and means selectively to interconnect the jaws either in position such that their surfaces of lesser curvature lie substantially in a single circular periphery or in position such that their surfaces of greater curvature lie substantially in a single smaller circular periphery.

2. In a tongs, the combination of a plurality of work gripping jaws adapted collectively to surround and grip work of different sizes, the jaws having substantially similar work engaging faces and each jaw having work engaging surfacesof two dif ferent circular curvatures, the surface of greater curvature lying outside the curvature, prolonged, of the surface of lesser curvature, and means selectively to interconnect the jaws either in position such that their surfaces of lesser curvature lie substantially in a single circular periphery or in position such that their surfaces of greater curvature lie substantially in a single smaller circular periphery;

3. In 'a tongs, the combination of a plurality of work gripping jaws adapted collectively to surround and grip work of different sizes, the jaws having substantially similar work engaging faces and each jaw having work engaging surfaces of two different curvatures, and means selectively to interconnect the j aws either in position such that their surfaces of lesser curvature lie substantially in a single circular periphery or in position such that their surfaces of greater curvature lie substantially in a single smaller circular periphery, said means embodying a multiple-step latch device mounted upon and operating between adjacent ends of two adjacent aws.

4. In a tongs, the combination of a plurality of work gripping jaws adapted collectively to surround and grip work of different sizes, the jaws having substantially similar work engaging faces and each jaw having work engaging surfaces of two different circular curvatures, the surface of greater curvature lying outside the curvature, prolonged, of the surface of lesser curvature, and means selectively to interconnect the jaws either in position such that their surfaces of lesser curvature lie sub stantially in a single circular periphery or in position such that their surfaces of greater curvature lie substantially in a single smaller circular periphery, said means embodying a multiple step latch device mounted upon and operating between adjacent ends of two adjacent jaws.

In witness that I claim the foregoing I have hereunto subscribed my name this 3rd day of November, 1924.

ROBERT ADAMS. 

